Combined with upgrading and expansion engineering of sewage treatment plant in northern suburbs the structural design and construction of extra caisson of pumping station is introduced.

Extra caisson is widely used as one of deep foundation with the development of construction technology and machinery.

This paper introduces the main manufacture technologies and sinking method of large caisson.

Aiming at soft foundation soil,this paper emphasizes on quality control of large caisson constructions.

Discussion on fabrication technology of large open caisson;

Taking the SB pump room well sinking at Shanghai Pudong as engineering background, close up photogrammetry has been applied to measuring the displacements in the process of large scale well sinking at first by establishing the digit PHOTO analysis system.

Close up photogrammetry was applied to measuring the displacements of all the process of large scale well sinking by establishing visual digit close up photogrammetry system based on the PHOTO measuring analysis system and Auto CAD and Matlab software.